Many millions of venipuncture procedures are performed each year in hospitals in the United States. In such procedures, a cannula, which may be a steel needle or a plastic tube, is inserted in a vein with the exterior end of the cannula being fitted with a hub adapted for connection to a tube through which fluids of various types are to be intravascularly administered. In the most common venipuncture procedure, a cannula, usually either a hollow steel needle or a plastic tube within which is carried a rigid, removable sharpened stylet, is passed through the skin and into the lumen of a vein. Tubing is then attached to the hub of the cannula, and is commonly taped to the patient's skin. To anchor the cannula in place, strips torn from a roll of adhesive tape commonly are wound about the hub of the cannula and the ends of each strip are adhered to the patient's skin on either side of the venipuncture site to restrain back and forth movements of the hub and cannula. One or more further strips of protective adhesive tape are then adhered to the skin over the venipuncture site to further stabilize the cannula. The vascular puncture site itself may be treated with an antiseptic to reduce infection.
The taping of the hub of the cannula in place against the skin, as described above, is time consuming, requires considerable harmful manipulation of the cannula and hub, and completely shields from view not only the venipuncture site but also the cannula hub itself. Cannula hubs are commonly of plastic and are generally color coded to signal the diameter of the cannula. For certain procedures, it is necessary that the cannula diameter be able to be determined without the necessity of withdrawing the cannula from the vein and inserting a separate cannula.
Unfortunately, vascular puncture wounds often become infected, and postinfusion phlebitis may occur. The completed cannula site may be correctly considered to be an open surgical wound containing a foreign body. Bacteremia, the most serious infection complication related to infusion therapy, reportedly may occur in up to eight percent of patients with plastic catheters or cannulae in place. Contaminants leading to infection may be carried by the infusion devices, or may merely enter directly through vascular puncture wounds. In the latter situation, it appears that the likelihood of infection increases as the catheter is inadvertently manipulated during application of the catheter dressing or as the dressing is changed.
It is commonplace for health professionals to prepare for a vascular puncture procedure by tearing strips of tape from a roll, temporarily fastening the strips of tape to a convenient surface such as the edge of an operating room table, introducing the cannula into a vein, and then plucking the strips one by one from the side of the table to anchor the cannula hub in place. Such procedures, even when conducted in operating room conditions, are far from sterile.
As thus described, vascular puncture procedures in the past have involved the use of tape strips torn from a roll of tape by health professionals performing the procedures. The resulting dressings accordingly are not uniform, are not sterile, require an inordinate amount of time to prepare, require significant manipulation of the catheter and hub during application and changing of the dressing, and tend to shield both the vascular puncture wounds and the cannula hubs from view. Reference may be made to Arnold, et al, The Importance of Frequent Examination of Infusion Sites in Preventing Postinfusion Phlebitis, Surgery, Gynecology and Obstetrics, 145: 19-20 (1977); Stratton, Infection Related to Intravenous Infusion, Heart and Lung, Vol. II, No. 2, 1982, pp. 123-137; Maki, The Prevention and Management of Device-Related Infection in Infusion Therapy, Journal of Medicine, Vol. II, No. 4, 1980; and McIntyre et al, eds., Textbook of Advanced Cardiac Life Support, pub. by the American Heart Association, 1981, Chap. II.